NEET Biotechnology and Its Applications Test

• Answer: (4) All of the above
• Explanation: Techniques like RNAi, gene knockout, and antisense RNA prevent the expression of specific genes, silencing them.

• Answer: (1) Escherichia coli
• Explanation: Human insulin is produced in Escherichia coli by inserting the human insulin gene into bacterial plasmids.

• Answer: (1) Translation in nematode.
• Explanation: RNA interference (RNAi) is a process by which RNA molecules inhibit gene expression, typically by causing the degradation of mRNA or inhibiting its translation. In nematodes, RNAi primarily affects translation, thereby preventing the synthesis of certain proteins.

• Answer: (4) All of the above
• Explanation: Plasmids, liposomes, and bacteriophages can all serve as vectors to deliver genetic material into host cells.

• Answer: (1) PCR
• Explanation: Polymerase Chain Reaction (PCR) is used to amplify specific DNA sequences rapidly.

• Answer: (1) Identify transformed cells
• Explanation: Selectable markers, such as antibiotic resistance genes, help identify cells that have taken up the plasmid vector.

• Answer: (1) Penicillin
• Explanation: Secondary metabolites like penicillin are not directly involved in growth or reproduction but serve ecological functions.

• Answer: (2) Reverse transcriptase
• Explanation: Reverse transcriptase synthesizes complementary DNA (cDNA) from mRNA, commonly used in molecular cloning and gene expression studies.

• Answer: (1) Extraction, Amplification, Ligation, Transformation
• Explanation: The typical steps in gene cloning include extracting the DNA, amplifying the gene of interest, ligating it into a vector, and transforming it into a host organism for replication.

• Answer: (2) Exploitation of biological resources without permission
• Explanation: Biopiracy occurs when companies or researchers use indigenous biological resources without proper authorization or compensation.

• Answer: (2) DNA from two different sources combined
• Explanation: Recombinant DNA involves combining DNA from two different sources to create a new genetic combination used in genetic engineering.

• Answer: (2) Vitamin A
• Explanation: Golden rice is genetically modified to produce β-carotene, a precursor of vitamin A, to combat vitamin A deficiency in populations with limited access to this nutrient.

• Answer: (2) They transfer genes into plants.
• Explanation: Ti plasmids, derived from Agrobacterium tumefaciens, are used in plant genetic engineering to transfer genes into plant cells.

• Answer: (2) Synthesize DNA from RNA
• Explanation: Reverse transcriptase is an enzyme that synthesizes complementary DNA (cDNA) from an RNA template, commonly used in the study of gene expression.

Answer: (1) To identify successful transformants

Explanation: Selectable markers, like antibiotic resistance genes, help identify cells that have successfully incorporated the desired genetic material

• Answer: (1) It is used to create genetically modified organisms (GMOs).
• Explanation: Recombinant DNA technology is used to manipulate DNA and create GMOs by inserting genes from one organism into the DNA of another organism, making it widely applicable in agriculture, medicine, and research.

• Answer: (4) All of the above
• Explanation: Selectable markers such as antibiotic resistance genes, fluorescent proteins, and reporter genes are used to identify cells that have successfully incorporated foreign DNA.

• Answer: (4) All of the above
• Explanation: Plasmids are circular DNA molecules used in cloning because they replicate independently, have selectable markers, and contain restriction sites for gene insertion.

• Answer: (1) A plant resistant to pests
• Explanation: Transgenic organisms are genetically modified to express foreign genes, like pest-resistant plants with inserted Bt toxin genes.

• Answer: (3) DNA ligase
• Explanation: DNA ligase is referred to as the molecular glue because it joins DNA fragments by forming phosphodiester bonds.

• Answer: (3) Cloning animals
• Explanation: While recombinant DNA technology has applications in insulin production, genetically modified crops, and gene therapy, animal cloning typically involves other techniques, such as somatic cell nuclear transfer.

• Answer: (1) Escherichia coli
• Explanation: Recombinant DNA technology enables E. coli to produce human insulin by inserting the insulin gene into its genome.

• Answer: (1) Gel electrophoresis
• Explanation: Gel electrophoresis is used to separate DNA fragments by size, where smaller fragments move faster through the gel compared to larger ones.

• Answer: (3) To detect specific DNA or RNA sequences
• Explanation: Probes are short, labeled sequences of DNA or RNA used to identify complementary sequences through hybridization.

• Answer: (1) FISH
• Explanation: FISH uses fluorescent probes to locate specific DNA sequences on chromosomes.

• Answer: (2) Modifying cells outside the body and reintroducing them
• Explanation: In ex vivo gene therapy, cells are removed from the patient, modified in the laboratory, and then reintroduced into the body.

• Answer: (4) All of the above
• Explanation: Transgenic animals serve in research, medicine, and agriculture for studying genes, creating therapies, and disease modeling.

• Answer: (4) The toxin causes cell wall damage to Bacillus thuringiensis.
• Explanation: Bt toxin is produced by Bacillus thuringiensis and is toxic to certain insects, not to the bacterium itself. The toxin disrupts the gut cells of insects, causing their death. It is also used in genetically modified crops to protect against pests.

• Answer: (2) A mouse with a specific gene inactivated
• Explanation: Knockout mice are used in research to study the role of specific genes by inactivating them.

• Answer: (4) All of the above
• Explanation: Various methods, including electroporation, gene guns, and microinjection, are used to create genetically modified plants by introducing foreign genes into plant cells.

• Answer: (2) Vitamin A deficiency
• Explanation: Golden rice contains β-carotene, which the body converts into vitamin A, addressing vitamin A deficiency in developing countries.

• Answer: (4) All of the above
• Explanation: Bioinformatics integrates computational tools to analyze data in genomics, proteomics, and drug discovery.

• Answer: (1) Gel electrophoresis
• Explanation: Gel electrophoresis separates DNA fragments based on size using an electric field.

• Answer: (1) Polymerase Chain Reaction
• Explanation: PCR is a technique used to amplify specific DNA sequences, making millions of copies of a particular segment of DNA in a short time.

• Answer: (4) All of the above
• Explanation: Gene therapy faces challenges like immune responses, limitations in treating complex disorders, and high costs.

• Answer: (2) Northern blotting
• Explanation: Northern blotting detects RNA sequences using labeled probes, while Southern and Western blotting are used for DNA and proteins, respectively.

• Answer: (2) Herbert Boyer and Stanley Cohen
• Explanation: Boyer and Cohen pioneered recombinant DNA technology by combining DNA from different sources using restriction enzymes and ligase.

• Answer: (2) Join DNA fragments
• Explanation: DNA ligase seals the nicks in the sugar-phosphate backbone of DNA, joining fragments together.

• Answer: (4) All of the above
• Explanation: These are types of genetic markers used to identify variations in DNA sequences for forensic and paternity analyses.

• Answer: (2) It is synthesized from an RNA template.
• Explanation: cDNA (complementary DNA) is synthesized from an RNA template using reverse transcriptase and lacks introns.

• Answer: (4) All of the above
• Explanation: These crops were genetically engineered for specific purposes: pest resistance (Bt cotton), enhanced nutrition (Golden rice), and extended shelf life (Flavr Savr tomato).

• Answer: (4) All of the above
• Explanation: Biotechnology improves agriculture through pest-resistant crops, biofertilizers, and transgenic plants with enhanced traits.

• Answer: (4) Plasmids are essential for the survival of the host cell.
• Explanation: While plasmids can provide advantages like antibiotic resistance, they are not essential for the survival of the host cell, as the cell can live without them.

• Answer: (4) Organism
• Explanation: Cloning vectors are used to carry foreign DNA into host cells for cloning. Organisms are not vectors themselves but may be hosts for cloned genes.

• Answer: (3) Joining DNA fragments
• Explanation: DNA ligase is an enzyme used to join DNA fragments by forming phosphodiester bonds between the sugar-phosphate backbones of the DNA.

• Answer: (2) Bacillus thuringiensis
• Explanation: Bt cotton is genetically modified to express a toxin from Bacillus thuringiensis that is lethal to specific insect pests.

• Answer: (1) Agrobacterium
• Explanation: The first genetically modified plant was produced using Agrobacterium tumefaciens, which naturally transfers DNA to plant cells, making it a tool in plant genetic engineering.

• Answer: (1) Electroporation
• Explanation: Electroporation is a technique used to introduce recombinant DNA into cells by applying an electrical field, making the cell membrane temporarily permeable.

• Answer: (2) Vector for gene transfer
• Explanation: The Ti plasmid from Agrobacterium tumefaciens is used as a vector to transfer genes into plant cells, particularly for creating genetically modified plants.

• Answer: (4) All of the above
• Explanation: These methods are commonly used in genetic engineering to introduce DNA into cells for transformation.